const cfg = require('./config.js'),
  isLetter = c => (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z');

function CssHandler(tagStyle) {
  var styles = Object.assign(Object.create(null), cfg.userAgentStyles);
  for (var item in tagStyle)
    styles[item] = (styles[item] ? styles[item] + ';' : '') + tagStyle[item];
  this.styles = styles;
}
CssHandler.prototype.getStyle = function (data) {
  this.styles = new parser(data, this.styles).parse();
}
CssHandler.prototype.match = function (name, attrs) {
  var tmp, matched = (tmp = this.styles[name]) ? tmp + ';' : '';
  if (attrs.class) {
    var items = attrs.class.split(' ');
    for (var i = 0, item; item = items[i]; i++)
      if (tmp = this.styles['.' + item])
        matched += tmp + ';';
  }
  if (tmp = this.styles['#' + attrs.id])
    matched += tmp + ';';
  return matched;
}
module.exports = CssHandler;

function parser(data, init) {
  this.data = data;
  this.floor = 0;
  this.i = 0;
  this.list = [];
  this.res = init;
  this.state = this.Space;
}
parser.prototype.parse = function () {
  for (var c; c = this.data[this.i]; this.i++)
    this.state(c);
  return this.res;
}
parser.prototype.section = function () {
  return this.data.substring(this.start, this.i);
}
// 状态机
parser.prototype.Space = function (c) {
  if (c == '.' || c == '#' || isLetter(c)) {
    this.start = this.i;
    this.state = this.Name;
  } else if (c == '/' && this.data[this.i + 1] == '*')
    this.Comment();
  else if (!cfg.blankChar[c] && c != ';')
    this.state = this.Ignore;
}
parser.prototype.Comment = function () {
  this.i = this.data.indexOf('*/', this.i) + 1;
  if (!this.i) this.i = this.data.length;
  this.state = this.Space;
}
parser.prototype.Ignore = function (c) {
  if (c == '{') this.floor++;
  else if (c == '}' && !--this.floor) {
    this.list = [];
    this.state = this.Space;
  }
}
parser.prototype.Name = function (c) {
  if (cfg.blankChar[c]) {
    this.list.push(this.section());
    this.state = this.NameSpace;
  } else if (c == '{') {
    this.list.push(this.section());
    this.Content();
  } else if (c == ',') {
    this.list.push(this.section());
    this.Comma();
  } else if (!isLetter(c) && (c < '0' || c > '9') && c != '-' && c != '_')
    this.state = this.Ignore;
}
parser.prototype.NameSpace = function (c) {
  if (c == '{') this.Content();
  else if (c == ',') this.Comma();
  else if (!cfg.blankChar[c]) this.state = this.Ignore;
}
parser.prototype.Comma = function () {
  while (cfg.blankChar[this.data[++this.i]]);
  if (this.data[this.i] == '{') this.Content();
  else {
    this.start = this.i--;
    this.state = this.Name;
  }
}
parser.prototype.Content = function () {
  this.start = ++this.i;
  if ((this.i = this.data.indexOf('}', this.i)) == -1) this.i = this.data.length;
  var content = this.section();
  for (var i = 0, item; item = this.list[i++];)
    if (this.res[item]) this.res[item] += ';' + content;
    else this.res[item] = content;
  this.list = [];
  this.state = this.Space;
}